Stern drive hydraulic trim control system including a tilt position indicator

ABSTRACT

A stern drive unit including a stern drive leg fixed to the rear of an engine and including a part which is tiltable vertically and swingable horizontally independently of the engine, together with a rearwardly located elastomeric mount connected to the stern drive unit and adapted for connection to a boat hull for vibrationally isolating and supporting the stern drive unit from the boat hull and for providing a pivotal axis relative to which the stern drive unit is tiltable relative to the boat hull, an elastomeric part, a bracket fixed to the elastomeric part and adapted to be fixed to the boat hull, an arm fixed to the elastomeric part remotely from the bracket, and a jacking mechanism connected between the engine and the arm for tilting the stern drive unit relative to the boat hull while also supporting and vibrationally isolating the engine from the boat hull.

United States Patent 1191 Lambrecht et al.

1 Dec. 30, 1975 [54] STERN DRIVE HYDRAULIC TRIM CONTROL SYSTEM INCLUDING A TILT POSITION INDICATOR [75] Inventors: Ralph E. Lambrecht, Lake Bluff;

Harry Najimian, Jr., Lake Forest, both of Ill.

[73] Assignee: Outboard Marine Corporation,

Waukegan, Ill.

[22] Filed: Nov. 18, 1974 [21] Appl. No.: 524,400

[52] US. Cl. 115/41 HT; 115/35 [51] Int. Cl. B63H 5/12 3,844,247 l0/l974 Collis et al. ll5/4l HT Primary Examiner-Trygve M. Blix Assistant ExaminerDouglas C. Butler Attorney, Agent, or Firm-Michael, Best & Friedrich [57] ABSTRACT A stern drive unit including a stern drive leg fixed to the rear of an engine and including a part which is tiltable vertically and swingable horizontally independently of the engine, together with a rearwardly located elastomeric mount connected to the stern drive unit and adapted for connection to a boat hull for vibrationally isolating and supporting the stern drive unit from the boat hulLand for providing a pivotal axis relative to which the stern drive unit is tiltable relative to the boat hull, an elastomeric part, a bracket fixed to the elastomeric part and adapted to be fixed to the boat hull, an arm fixed to the elastomeric part remotely from the bracket, and a jacking mechanism connected between the engine and the arm for tilting the stern drive unit relative to the boat hull while also supporting and vibrationally isolating the engine from the boat hull 7 Claims, 4 Drawing Figures US. Patent Dec. 30, 1975 Sheet2of2 3,929,089

STERN DRIVE HYDRAULIC TRIM CONTROL SYSTEM INCLUDING A TILT POSITION INDICATOR BACKGROUND OF THE INVENTION Attention is also directed to the US. Collis Application Ser. No. 321,049 filed Jan. 4, 1973, which application discloses a tilt position indicating arrangement.

SUMMARY OF THE INVENTION The invention provides a stern drive unit comprising a stern leg fixed to the rear of an engine and including a part which is tiltable vertically and horizontally swingable, together with elastomeric mounting means connected to the stern drive unit rearwardly of the front of the engine and adapted for connection to a boat hull for vibrationally isolating and supporting the stern drive unit from the boat hull and for providing a pivotal axis relative to which the stern drive unit is tiltable relative to the boat hull, and means located forwardly of the elastomeric mounting means for tilting the stern drive unit about the elastomeric mounting means and for vibrationally isolating and supporting the stern drive unit from the boat hull. The isolating, supporting, and tilting means comprises a mount including an elastomeric part, a bracket fixed to the elastomeric part and adapted to be fixed to the boat hull, an arm fixed to the elastomeric part in spaced relation from the bracket, and a jacking mechanism connected between the engine and the arm for tilting the stern drive unit relative to the boat hull.

In accordance with one preferred embodiment of the invention, the jacking mechanism comprises a hydraulic cylinder-piston means including a piston fixed to the arm and a hydraulic cylinder which receives the piston and which is fixed to the engine, together with means for selectively supplying hydraulic fluid to the cylinder to relatively displace the cylinder and the piston.

In further accordance with one embodiment of the invention, the stern drive unit further includes means for indicating the trim position of the stern drive unit relative to the boat and including a variable resistor fixed to the cylinder and a slide member guided for movement in engagement with the resistor and fixed to the arm, whereby the slide member moves relative to the resistor in response to relative movement between the cylinder and the piston so as thereby to vary the resistance of the resistor.

In still further accordance with one embodiment of the invention, the engine includes a V-shaped block with the apex thereof pointing downwardly, the rearwardly located elastormeric mounting means includes an elastormeric part on each side of the engine, and the isolating, supporting and tilting means comprises means for selectively supplying hydraulic fluid, a tie bar extending transversely beneath the engine, and, on each side of the engine, a mount including an elastormeric part fixed to the tie bar, a bracket fixed to the elastormeric part in spaced relation from the tie bar and adapted to be fixed to the boat hull, a hydraulic cylinder fixed to the engine and connected to the hydraulic fluid supply means, and a piston received in the cylinder and fixed to the tie bar. Preferably, all of the elastormeric parts are approximately located in a generally horizontally common plan so as to optimize vibration isolation of the V-block engine.

One of the principal features of the invention is the provision of a stern drive unit in which a jacking mechanism is interposed between a forward engine vibration isolating support mount and the engine.

Another of the principal features of the invention is the provision of a jacking mechanism for tilting of a stern drive unit about a horizontal axis, which jacking mechanism is located between the engine and a forwardly located-vibration isolating and stem drive supporting mount.

Another of the principal features of the invention is the provision 'of a stern drive unit in which a jacking mechanism is interposed between a forward engine vibration isolating and supporting mount and the engine and wherein the engine includes a V-block sup ported on each side by fore and aft mounts located in a common plane.

Another of the principal features of the invention is the provision of a hydraulicly actuated mechanism for tilting a stern drive unit.

Still another of the principal features of the invention is the provision of a stern drive unit including a tilting mechanism comprising a hydraulic cylinder which is fixed to the engine and a piston which is movable relative to the cylinder in response to the application to the cylinder of pressure fluid, and which is connected to a vibration isolating mount which supports the engine.

Still another ofthe principal features of the invention is the provision of a stern drive unit tilting mechanism which is economical to construct and which will provide long and reliable service over a long and useful life.

Other features and advantages of the invention will become known by reference to the following drawings, general description, and claims.

THE DRAWINGS FIG. 1 is a fragmentary, side elevational view, partially in section, of a boat including a stern drive unit incorporating various of the features of the invention.

FIG. 2 is a schematic view of the tilting or jacking arrangement incorporated in the stern drive unit shown in FIG. 1.

FIG. 3 is an enlarged view of a portion of the stern drive unit shown in FIG. 1.

FIG. 4 is a partially schematic fragmentary sectional view taken generally along line 44 of FIG. 3.

Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purposes of description and should not be regarded as limiting.

GENERAL DESCRIPTION Shown in the drawings is a stern drive unit 11 mounted at the rear of a boat hull 13 and including an engine 15 and connected propulsion unit 17 comprising a leg, part, or lower unit 19 which includes a shaft 20 carrying a propeller and which is vertically tiltable and horizontally steerable relative to the engine 15. Any suitable stern drive unit construction can be employed. However, in the illustrated construction, the engine includes a V-shaped block member which is arranged with the apex thereof pointing downwardly.

At the rear, the engine 15 is mounted, on each side of the boat hull 13, through elastormeric mounts 23 of rubber or other resilient material, which mounts 23 are described in greater detail in US. Pat. No. 3,722,456 issued Mar. 27, 1973. As in US. Pat. No. 3,722,456, the rearward rubber mounts 23 vibrationally isolate and support the stern drive unit 11 as well as afford tilting of the stern drive unit 11 about a generally horizontal axis and relative to the boat hull 13 so as to provide a trim adjustment, i.e., to provide a fine tilting adjustment of the stern drive unit 11 to facilitate horizontally locating the propeller shaft 20.

In accordance with the invention, there is also provided, forwardly of the rearward resilient mounts 23, a forward resilient means for mounting the stern drive unit 11 from the boat hull l3 and hydraulically operated means connected between the forward resilient mounting and the engine 15 for displacing the engine 15 relative to the forward resilient mounting means and thereby tilting the stern drive unit 11 about the rearward mounts 23 to obtain fine trim adjustment.

More specifically with respect to the forward mounting means, in the illustrated construction, such means is located adjacent to the mid section of the engine 15 and comprises, on each side of the engine, a bracket 25 which is fixed to the boat hull 13 and in any suitable manner such as by one or more bolts 27 and which includes, as shown best in FIGS. 3 and 4, spaced upper and lower portions 29 and 31, respectively, which include aligned bores 33.

Extending into the space between the upper and lower portions 27 and 31, respectively, of each of the brackets 25 are respective arms which include a mount portion 37 having an aperture 39 into which extends an elastomeric part or mount 41 in the form of a mass of rubber or other resilient mounting material, which rubber mass continuously engages the aperture 39 and the margins of the aperture 39 on the upper and lower surfaces of the arm portion 37. The rubber mass 41 is bonded to a sleeve 43 including an internal thread and is fixed to the arm portion 37 by upper and lower clamping plates 45 and 47, respectively, which plates are joined together by a plurality of bolts which extends through the arm portion 37, and are threaded into the lower plate 47. If desired the mount 41 and sleeve 43 can be formed in two parts for insertion into the aperture 39 from the top and bottom.

Each arm 35 and the attached elastomeric mount 41 is fixed to the adjacent bracket 25 by a bolt 51 which passes through the bores in the bracket portions 29 and 31, which extends through enlarged holes 53 in the clamping plates 45 and 47 in spaced relation thereto, and which is threaded into the sleeve 43, and into a nut 55 so as to rigidfy the bracket 25, bolt 51, and sleeve 43, while permitting free movement of the arm 35 4 relative to the bracket 25 subject to the resilience of the elastomeric mount 41.

The transversely spaced arms 35 are fixedly connected together by a transverse tie bar 57. If desired, the arms 35 and tie bar 57 could be fabricated unitarily. In turn, the arms 35 (or tie bar 57) are respectively connected to the respective piston rods 59 of a pair of transversely spaced hydraulic cylinder-piston assemblies 61 which are respectively mounted on the opposite sides of the engine 15. More specifically, on each side of the engine 15, a cylinder housing 63 is fixed to the engine 15 by means including a pair of vertically extending bolts 65 which are spaced fore and aft and by means of a set screw 67 which is located approximately midway between the bolts 65 and which extends upwardly and toward the center plane of the engine 15 at an angle of about 45 degrees. Each of the cylinder housings includes a vertically orientated and downwardly open cylinder 69 which contains a piston 71 connected to one of the piston rods 59 and which is closed, at the bottom thereof, by an apertured end cap 73 through which the connected piston rod 59 extends.

Accordingly, application of fluid pressure within the cylinders 69 above or below the pistons 71 will cause the cylinder housings 63 to rise or fall relative to the pistons 71 and thereby elevate or depress the engine 15 so as thereby to tilt the stern drive unit about the rearward elastormeric mounts 23.

Any suitable means can be provided for selectively supplying hydraulic fluid to be opposed ends of the cylinder 69. In the illustrated construction, such means comprises, as shown schematically in FIG. 2, an electrically driven reversable pump 81 which communicates through parallel conduits or ducts 83 and 85 to a reservoir or sump 87 and to the opposite ends of a spool valve cavity 89. In turn, the left end of the spool valve cavity 83 is connected through a spring biased check valve 91, and through a conduit 93 to the upper ends of the cylinders 69. The other end of the spool valve cavity 89 is connected through a spring biased check valve 95 and through a conduit 97 to the lower ends of the cylinders 69.

Also in accordance with the invention, there is provided means for indicating the trim position of the stern drive unit 11. While various other constructions could be employed, in the illustrated construction, such means comprises (See FIG. 4) a gauge or meter 101 which is connected to a suitable source of constant voltage such as, for instance, a battery 103, which is sensitive to the applied voltage, and which is also connected to a variable resistor 105 arranged so that tilting movement of the engine 15 causes variation in the resistance of the resistor 105. More particularly, in the preferred construction, the variable resistor 105 comprises a vertically extending coil 107 which is fixed in a housing 109 attached to the cylinder housing 63, together with a wiper or slide member 111 which is fixed at its lower end to one of the arms 35 by suitable means, such as a screw 113, and which extends upwardly and into the resistor housing 109 for guided movement therein and for variable engagement with the coil 107 depending upon the position of the engine 15 relative to the arms 35.

Preferably, the slide member 111 is electrically connected by a wire 115 or by other suitable means to the engine block member 21 so as to complete an electrical circuit.

While it is preferred to employ the illustrated dual hydraulic cylinder-piston assemblies 61 which are connected to a tie bar 57 supported at its ends by the elastormeric mounts 41, the invention is also applicable to a single hydraulic cylinder-piston assembly or other jacking mechanism connected between an engine and one or more elastormeric mounts 41 supported by the boat hull 13.

In the illustrated construction, in which the engine 15 includes a V-shaped block member 21 having its apex pointed downwardly, it is preferred, in order to achieve maximum vibration isolation, that all of the elastormeric mounts 23 and 41 be approximately located in a generally horizontal common plane 121. (See FIG. 1).

In operation, supply of pressure fluid to the top of the cylinders 69 (and drainage of pressure fluid from the bottom of the cylinder 69) effects lifting of the forward end of the engine 15 so as thereby to tilt the stern drive unit 11 in the clockwise direction about the rearward elastormeric mounts 23. Supply of pressure fluid to the bottom of the cylinders 69 (and drainage of pressure fluid from the top of the cylinder 69) effects lowering of the forward part of the engine 15 and consequent tilting of the stern drive unit 11 in a counter clockwise direction about the rearward elastormeric mounts 23. At the same time, the forward and rearward mounts 23 and 41 serve to isolate the boat hull 13 from engine vibration.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

l. A stern drive unit comprising an engine, a stern drive leg fixed to the rear of said engine and including a part which is tiltable vertically and swingable horizontally independently of said engine, elastomeric mounting means connected to said stern drive unit rearwardly of the front of said engine and adapted for connection to a boat hull for vibrationally isolating and supporting said stern drive unit from the boat hull and for providing a pivotal axis relative to which said stern drive unit is tiltable relative to the boat hull, and means located forwardly of said elastomeric mounting means for tilting said stern drive unit about said elastomeric mounting means and for vibrationally isolating and supporting said stern drive unit from the boat hull, said isolating, supporting and tilting means comprising a mount including an elastomeric part, a bracket fixed to said elastomeric part and adapted to be fixed to the boat hull, an arm fixed to said elastomeric part remotely from said bracket, and ajacking mechanism connected between said engine and said arm for tilting said stern drive unit relative to the boat hull.

2. A stern drive unit in accordance with claim 1 wherein said jacking mechanism comprises a hydraulic cylinder piston means including a piston fixed to one of said arm and said engine, and a hydraulic cylinder 6 which receives said piston and which is fixed to the other of said engine and said arm, and means for selectively supplying hydraulic fluid to said cylinder to relatively displace said cylinder and said piston.

3. A stern drive unit in accordance with claim 2 wherein said piston is fixed to said arm and said cylinder is fixed to said engine.

4. A stern drive unit in accordance with claim 3 and further including means for indicating the tilt position of said stern drive unit relative to the boat and including a variable resistor fixed to said cylinder and a slide member guided for movement in engagement with said resistor and fixed to said arm, whereby said slide member moves relative to said resistor in response to relative movement between said cylinder and said piston so as thereby to vary the resistance of said resistor.

5. A stern drive unit comprising an engine, a stern drive leg fixed to the rear of said engine and including a part which is tiltable vertically and swingable horizontally independently of said engine, elastomeric mounting means connected to said stern drive unit on each side thereof and rearwardly of the front of said engine and adapted for connection to a boat hull for vibrationally isolating and supporting said stern drive unit from the boat hull and for providing a pivotal axis relative to which said stern drive unit is tiltable relative to the boat hull, and means located forwardly of said elastomeric mounting means for tilting said stern drive unit about said elastomeric mounting means and for vibrationally isolating and supporting said stern drive unit from the boat hull, said isolating, supporting and tilting means comprising means for selectively supplying hydraulic fluid, a tie bar extending transversely beneath said engine, and, on. each side of said engine, a mount including an elastomeric part fixed to said tie bar, a bracket fixed to said elastomeric part remotely from said tie bar and adapted to be fixed to the boat hull, a hydraulic cylinder fixed to said engine and connected to said hydraulic fluid supply means, and a piston received in said cylinder and fixed to said tie bar.

6. A stern drive unit in accordance with claim 5 and further including means for indicating the tilt position of said stern drive unit relative to the boat and including a variable resistor fixed to one of said cylinders and a slide member guided for movement in engagement with said resistor and fixed to said tie bar, whereby said slide member moves relative to said resistor in response to tilting movement of said stern drive unit so as thereby to vary the resistance of said resistor.

7. A stern drive unit in accordance with claim 5 wherein said engine includes a V-shaped block with the apex thereof pointed downwardly, wherein said elastomeric mounting means each includes an elastomeric part, and wherein said elastomeric parts are approximately located in a common generally horizontal plane. 

1. A stern drive unit comprising an engine, a stern drive leg fixed to the rear of said engine and including a part which is tiltable vertically and swingable horizontally independently of said engine, elastomeric mounting means connected to said stern drive unit rearwardly of the front of said engine and adapted for connection to a boat hull for vibrationally isolating and supporting said stern drive unit from the boat hull and for providing a pivotal axis relative to which said stern drive unit is tiltable relative to the boat hull, and means located forwardly of said elastomeric mounting means for tilting said stern drive unit about said elastomeric mounting means and for vibrationally isolating and supporting said stern drive unit from the boat hull, said isolating, supporting and tilting means comprising a mount including an elastomeric part, a bracket fixed to said elastomeric part and adapted to be fixed to the boat hull, an arm fixed to said elastomeric part remotely from said bracket, and a jacking mechanism connected between said engine and said arm for tilting said stern drive unit relative to the boat hull.
 2. A stern drive unit in accordance with claim 1 wherein said jacking mechanism comprises a hydraulic cylinder piston means including a piston fixed to one of said arm and said engine, and a hydraulic cylinder which receives said piston and which is fixed to the other of said engine and said arm, and means for selectively supplying hydraulic fluid to said cylinder to relatively displace said cylinder and said piston.
 3. A stern drive unit in accordance with claim 2 wherein said piston is fixed to said arm and said cylinder is fixed to said engine.
 4. A stern drive unit in accordance with claim 3 and further including means for indicating the tilt position of said stern drive unit relative to the boat and including a variable resistor fixed to said cylinder and a slide member guided for movement in engagement with said resistor and fixed to said arm, whereby said slide member moves relative to said resistor in response to relative movement between said cylinder and said piston so as thereby to vary the resistance of said resistor.
 5. A stern drive unit comprising an engine, a stern drive leg fixed to the rear of said engine and including a part which is tiltable vertically and swingable horizontally independently of said engine, elastomeric mounting means connected to said stern drive unit on each side thereof and rearwardly of the front of said engine and adapted for connection to a boat hull for vibrationally isolating and supporting said stern drive unit from the boat hull and for providing a pivotal axis relative to which said stern drive unit is tiltable relative to the boat hull, and means located forwardly of said elastomeric mounting means for tilting said stern drive unit about said elastomeric mounting means and for vibrationally isolating and supporting said stern drive unit from the boat hull, said isolating, supporting and tilting means comprising means for selectively supplying hydraulic fluid, a tie bar extending transversely beneath said engine, and, on each side of said engine, a mount including an elastomeric part fixed to said tie bar, a bracket fixed to said elastomeric part remotelY from said tie bar and adapted to be fixed to the boat hull, a hydraulic cylinder fixed to said engine and connected to said hydraulic fluid supply means, and a piston received in said cylinder and fixed to said tie bar.
 6. A stern drive unit in accordance with claim 5 and further including means for indicating the tilt position of said stern drive unit relative to the boat and including a variable resistor fixed to one of said cylinders and a slide member guided for movement in engagement with said resistor and fixed to said tie bar, whereby said slide member moves relative to said resistor in response to tilting movement of said stern drive unit so as thereby to vary the resistance of said resistor.
 7. A stern drive unit in accordance with claim 5 wherein said engine includes a V-shaped block with the apex thereof pointed downwardly, wherein said elastomeric mounting means each includes an elastomeric part, and wherein said elastomeric parts are approximately located in a common generally horizontal plane. 